Nibbling machine



June 8, 1954 A. KAUFMANN NIBBLING MACHINE 2 Sheets-Shet 1 Filed March 13, 1950 t mm mm R @N m K! 7 H 2 1U i w N 8 .9 .2 2 m Q 2 A u m m l F W m N P t June 8, 1 954 KAUFMANN 2,680,292

NIBBLING MACHINE Filed March 13, 1950 2 Sheets-Sheet 2 1N VENTOR QLaE QT KAUFMANN ATTORNEY Patented June 8, 1954 NIBBLING MACHINE Albert Kaufmann, Zuchwil, Switzerland, assignor to Scintilla Aktien-Gesellschaft, Solothurn,

Switzerland, a joint-stoc land k company of Switzer- Application March 13, 1950, Serial No. 149,388

Claims priority, application Switzerland September 29, 1949 I 3 Claims.

' This invention relates to nibbling machines, i. e. to high-speed punching devices, and more especially to the type of portable nibblers provided with means for limiting the feed of the sheet material to be cut between two working strokes to a predetermined maximum.

'The hand-operated nibblers are provided with a reciprocating punch which cooperates with a die located in its path.

In the use of these hand-applied nibblers difiiculties have been encountered for instance when cutting out a circular section of a work-piece which is fixed in position, because it then becomes necessary to turn the nibbler as a whole through 360 about its punching axis. Since the nibbler has the driving motor mounted in its handle. its length in horizontal direction frequently meets an obstacle which renders it impossible to turn the device about its working head through a complete circle. Working in such a way has moreover proved to be very awkward.

It is an object of this invention to improve portable nibblers as hitherto used by making the punch and the die cooperating with it capable of being rotated manually by the operator through a full circle, while the tool is in operation.

In the drawings afiixed to this specification and forming part thereof an embodiment of this invention is illustrated diagrammatically by way of example.

In the drawing:

Fig. 1 is a side view, partly in axial section;

Fig. 2 is a cross-section on the line A-A in Fig. 1;

Fig. 3 is a cross-section on the line B B in Fig. 1 viewed from below;

Fig. 4 is a cross-section viewed from above on the line CC in Fig. 1;

Fig. 5 is an elevation of the punching die;

Fig. 6 is a vertical section of the manually movable head or guide surrounding the punching tool and of the die seated in its carrier; and

Fig. 7 is a view of a horizontal section on the line VII-VII in Fig. 6, looking in the direction of the arrows, showing the punching tool in position in a perforation of a metal plate operated upon by the tool.

Referring to the drawing, I is the motor casing, 2 is the motor shaft and 3 is a pinion on this shaft which meshes with a larger gear 4 of a reduction gearing, being mounted together with the pinion 5 on a stationary axle 6 which is supported in the motor casing and the gear case 1 respectively. This case is fixed to the motor casing I by means of screw bolts 8. Another axle 9 mounted in both casings supports the last gear II) of the reduction gearing. Screws such as II or other means may be provided to prevent the axles from turning.

The gear III is formed with an eccentric hub I0 loosely embraced by the annular head of a rod I 2 and is turned continuously, but at reduced speed when the motor is running.

The gear case ends, perpendicular to the motoraxis, in a cylindrical extension I3 the circumferential surface of which is threaded, and is formed with a central bore containing a cylindrical liner I4 which serves as a guide for the cross head linking the eccentric rod I2 to the head 20 of the punching tool I9.

The punching tool extends through a tool head I5 projecting into the liner I4 with a short neck I6 and having a flange I1 formed around its top.

A threaded cap I8 screwed on the casing ex- 7 tension I3 holds the tool head I5 applied against the bottom of extension I3, the axial length of the cap I8 being such that on the cap being screwed down on the said extension the head I5 remains fit to be turned by hand.

The punch I9 is axially reciprocable in the central boring of the head I5 and its top 20 is so dimensioned as to fit in the liner I4 for ready being rotated, reciprocates in the bore of the head I5.

The nibbling tool I9 is a cylindrical steel rod, to the lower end of which is fixed a cylindrical extension I9 of materially lesser diameter. The lower end of the cylindrical steel rod I9 forms the punch proper in the form of an edge I 9a which extends through a full circle and renders it possible to nibble the work 40 from the wall 4| (see Figs. 6 and '7) in any direction without turning the punch around its axis.

On the bottom end I 5' of the head I5 is mounted the punching die 32, and right above it the bottom end of the tool head I 5 is formed with a deep notch 22 extending near to 300 around the punch I9 and leaving the main body and the bottom end of the head I5 connected with each other only by a narrow neck 23 (Fig. 4). width of this notch is somewhat less than the length of stroke of the punch. The neck 23, being comparatively highly stressed by the rapidly succeeding punching or nibbling strokes, is preferably made of non-hardened high-duty material. The hardened steel punch preferably cooperates with a likewise hardened die. To this end the bore at the foot of the head is larger in diameter than the die and a part of its length is formed with screw thread, the remainder being conical. In this bore is removably inserted the threaded die 32 of hardened steel.

Since the tool head I5 is capable of circumferential movement through 360 in both directions relative to the gear case 1, the notch 22 can always be so adjusted as to take up that position which is most favorable for the operation which is going on at any time. In order to be able to fix the head with its notch in any desired position, a notched cap 24 is secured to the head 15, for instance by means of a set screw 25 (Fig. 1). and near the notches 26 of this cap a double armed locking lever 21, acted upon by a spring 30, is seated on an axle 29 fixed in the motor casing so as to extend into one of the notches 26 on the cap. By pressing on the free arm 21 of the locking lever, the cap 24 and the head can be released for circumferential adjustment. Near the lever 21 the motor switch 3| is arranged which can be operated by means of the same finger that releases the lever 21.

I wish it to be understood that I do not desire to be limited to the exact details shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. A nibbling machine, comprising a casing, a reciprocating ower-driven mechanism mounted in said casing, a punching tool rod secured with one of its ends to said power-driven mechanism to be reciprocated thereby, a punching edge all around said tool rod, a guiding sleeve mounted on said casing to be rotated around said tool rod which it guidingly surrounds, a die receiving and guiding the free end of said tool rod and means to firmly secure said die to said guiding sleeve,

said means exposing said punching edge between said die and said guiding sleeve.

2. A nibbling device, comprising a casing, a reciprocating power-driven mechanism mounted in said casing, a punching tool rod secured with one of its ends to said power-driven mechanism to be reciprocated thereby, a punching edge on and all around said tool rod, a guiding sleeve mounted on said casing to be manually rotated around said tool rod which it guidingly surrounds, latching means to hold said sleeve in a selected position on said casing, a die receiving and guiding the free end of said tool rod and means to firmly secure said die to said guiding sleeve, said means ex osing said punching edge between said die and said guiding sleeve.

3. A nibbling device, comprising a casing, a reciprocating power-driven mechanism mounted in said casing, a punching tool rod secured with one of its ends to said power-driven mechanism to be reciprocated thereby, a punching edge all around said tool rod, a guiding sleeve mounted on said casing to be freely rotated around said tool which it guidingly surrounds, latching means to hold said sleeve in a selected position on said casing, a die receiving and guiding the free end of said tool rod and a narrow neck integrally joining said die to said sleeve permitting a large portion of said punching edge to be exposed.

Beferences Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,958,941 Chapman May 15, 1934 2,033,662 Witt Mar, 10, 1936 2,182,544 Murrian Dec. 5, 1939 2,201,599 Trautmann May 21, 1940 2,278,174 Gray Mar. 31, 1942 2,376,590 Forss May 22, 1945 

